July 10, 2024
Reading Time: 3 minutes

• channelflowlib
• Requirements
• Creating the Project
• Installation of channelflowlib
• Sample Problem
• Analysis
• Breakdown
• Summary

Open channel analysis is one of the widely-used discipline in civil and hydraulics engineering for the analysis of both drainage and irrigation channels.

In this post, we will see how to analyze flow elements of a rectangular open channel using python and the library channelflowlib.

channelflowlib

channelflowlib is a python module for open channel flow analysis for hydraulics engineering. This is the library that we are going to use in this post.

Requirements

The following are the requirements in order to follow along.

• Code editor (VS Code or any)
• Python interpreter
• Knowledge of using a terminal/command prompt

Python should be installed in the computer in order for use to start using the library.

In order to navigate directories, install dependencies and running the program.

Creating the Project

In order to create the project, let's select a directory and create a new directory for our project. In mine, I will call it sample-rect short for "sample rectangular".

Windows

md sample-rect

Mac/Linux

mkdir sample-project

Then now create a new file, you can name it anything but I'll call mine main.py.

Next, let's create a virtual environment (optional) to store our dependencies in our project as project-wide and not globally.

virtualenv venv

Then to activate the virtual environment

Windows

venv\Scripts\activate

Mac/Linux

source ./venv/bin/activate

Installation of channelflowlib

Now to install the library that we are going to use

pip install channelflowlib

Sample Problem

Suppose we have a sample problem with the given data:

Given	Value
Discharge	1.0
Bed Slope	0.001
Base Width	1.0
Manning's n	0.015

In this case, our unknown is the water depth.

Analysis

Now in our code for the analysis of the problem:

In our main.py

from channelflowlib.openchannellib import Rectangular

# Initialize the object
rect = Rectangular(unknown='water_depth')

rect.discharge = 1.0
rect.channel_slope = 0.001
rect.channel_base = 1.0
rect.roughness = 0.015

rect.analyze()

# Display result
print(f"Water depth = {rect.water_depth}")

This would output

Water depth = 0.989

Breakdown

On line 1, we imported the library, specifically the Rectangular class.

Then on line 4, we initialized a rectangular channel object by specifying the unknown, in our problem, the unknown is 'water_depth'. You can set the unknown to be 'discharge', 'water_depth', 'channel_slope', and 'channel_base'.

Then line 6 - 9 sets the known properties of the channel. Any finally, on line 11, we call the analyze method to perform channel analysis.

Summary

You can now access other flow elements such as average velocity, wetted perimeter, cross sectional area of water, etc.

That's it for our tutorial today. I hope you can use this.